That's alright, I'm sure you'll get your sea legs pretty quickly.
It's a bit of both. Sometimes they disappear right in front of someone, and then we're pretty sure they're gone from this universe. Sometimes no one sees them go. In some cases we can determine that they're gone through the telepaths we have working in the Missing Persons department. But there's a few we still haven't confirmed, and we still don't know where anyone goes when they disappear from this world.
Haven, Maine, where there's a different flavor of crazy to wake up to every morning. You probably wouldn't believe half my stories if I told you.